• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.469-472
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• 2005

In this paper, we propose a new deinterlacing algorithm based on motion estimation and compensation with variable block size. Motion compensated methods using a fixed block size tend to produce undesirable artifacts when there exist complicated motion and high frequency components. In the proposed algorithm, the initial block size of motion estimation is determined based on the existence of global motion. Then, the block is divided depending on block characteristics. Since motion compensated deinterlacing may not always provide satisfactory results, the proposed method also use an intrafield spatial deinterlacing. Experimental results show that the proposed method provides noticeable improvements compared to motion compensated deinterlacing with a fixed block size.

• 방송공학회논문지
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• 제19권6호
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• pp.916-924
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• 2014

가변 블록크기를 적용하면 영상의 움직임 추정의 정확도를 향상시킬 수 있다. 그러나, 신축 움직임 추정에는 한계를 갖고 있다. 본 논문에서는 가변 블록크기로 신축 움직임을 추정하는 방법을 제안한다. 제안된 방법은 깊이 카메라로부터 얻어진 깊이 정보로부터 영상의 객체와 배경을 분리하고, 객체에 대해서만 깊이 정보를 이용하여 신축을 적용하며, 배경은 신축을 적용하지 않는다. 또한, 객체영역에는 움직임 추정의 정확도와 발생되는 움직임 벡터를 동시에 고려하여 효율적으로 가변블록 크기 모드가 선택된다. 모의실험을 바탕으로 제안된 방법의 움직임 추정의 정확도와 움직임 벡터수를 측정하였으며, 기존 신축 움직임 추정 방법에 비하여 동일한 움직임 추정의 정확도를 유지하면서 움직임 벡터의 수가 감소함을 확인하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.20-23
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• 1996

The block matching algorithm for the motion estimation is relatively simple to implement, and thus widely applied in image sequence coding such as H.261, MPEG- I and MPEG-2. Most techniques of the block matching method use fixed-size blocks for the motion estimation. And their success relies on the assumption that the motion within each block is uniform. But if the block size is increased to reduce the number of motion vectors for high data compression, the estimated image brings about many errors. In this paper, the variable-sized blocks are used to solve this problem. And the top down method is used to select the block size.

• 전자공학회논문지B
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• 제30B권4호
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• pp.104-115
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• 1993

The motion compensated coding (MCC) technique, which exploits the temporal redundancies in the moving images with the motion estimation technique,is one of the most popular techniques currently used. Recently, a variable block size(VBS) motion estimation scheme has been utilized to improve the performance of the motion compensted coding. This scheme allows large blocks to the used when smaller blocks provide little gain, saving rates for areas containing more complex motion. Hence, a new VBS motion estimation scheme with a hierarchical structure is proposed in this paper, in order to combine the motion vector coding technique efficiently. Topmost level motion vector, which is obtained by the gain/cost motion estimation technique with selective motion prediction method, is always transmitted. Thus, the hierarchical VBS motion estimation scheme can efficiently exploit the redundancies among neighboring motion vectors, providing an efficient motion vector encoding scheme. Also, a restricted search with respect to the topmost level motion vector enables more flexible and efficient motion estimation for the remaining lower level blocks. Computer simulations on the high resolution image sequence show that, the VBS motion estimation scheme provides a performance improvement of 0.6~0.7 dB, in terms of PSNR, compared to the fixed block size motion estimation scheme.

• 한국멀티미디어학회논문지
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• 제3권4호
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• pp.372-379
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• 2000

본 논문에서는 비트패턴을 기반으로 한 고속의 적응적 가변 블록 움직임 예측 알고리즘을 제안한다. 제안된 방법은 블록 내의 평균값을 기준으로 8bit 화소값을 0과 1의 비트패턴으로 변환한 후 블록의 움직임 예측을 수행한다. 비트변환을 통한 영상의 단순화는 움직임 추정의 계산적 부담을 감소시켜 빠른 탐색을 가능하게 한다. 그리고 블록 내의 움직임 정도를 미리 판별하여 이를 기반으로 한 적응적 탐색이 불필요한 탐색을 제거하고 움직임이 큰 블록에서는 정합 과정을 심화시켜 보다 빠르고 정확한 움직임 예측을 수행한다. 본 제안된 방식을 가지고 실험한 결과, 한 프레임 당 적은 수의 블록으로 고정된 크기의 블록을 가진 전역 탐색블록 정합 알고리즘(full search block matching algorithm; FS-BMA)보다 예측 에러를 적게 발생시켜 평균 0.5dB 정도의 PSNR 개선을 가져왔다.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2009년도 IWAIT
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• pp.381-384
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• 2009

In the Wyner-Ziv coding, compression performance highly depends on the quality of the side information since better quality of side information brings less channel noise and less parity bit. However, as decoder generates side information without any knowledge of the current Wyner-Ziv frame, it doesn't have optimal criterion to decide which block is more advantageous to generate better side information. Hence, in general, fixed block size motion estimation (ME) is performed in generating side information. By the fixed block size ME, the best coding performance cannot be attained since some blocks are better to be motion estimated in different block sizes. Therefore if there is a way to find appropriate ME block of each block, the quality of the side information might be improved. In this paper, we investigate the effects of variable block sizes of ME in generating side information.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -1
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• pp.7-10
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• 2000

Fast block motion estimation technique is proposed to reduce the computational complexity in video coding. In the conventional methods the size of search region is fixed. For small motion regions like background the small size of sea of search region is enough to find a block motion. But for active motion regions the large size of search region is preferred to figure out the accurate motion vector. Therefore, it is reasonable that a block motion is estimated in the variable search region (both the size and the position of it). That is to say, the search region varies according to the predicted motion characteristics of a block. The block motion in video frames has temporal continuity and then the search region of a current block is predicted using the block motion of previous blocks. The computational complexity of the proposed technique is significantly reduced with a good picture quality compared to the conventional methods.

• 전기전자학회논문지
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• 제20권1호
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• pp.111-114
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• 2016

HEVC에서는 가변 블록 크기마다 각각 독립적으로 움직임 추정을 수행하기 때문에 단일 블록 크기일 때보다 몇 배의 탐색 영역 데이터가 필요하며 조기 중단 기법의 적용도 어렵다. 본 논문에서는 가변 블록 크기에서도 탐색 영역 데이터를 재사용하고 조기 중단 기법도 적용하는 방법을 제안한다. 제안하는 방법을 TZS 알고리즘에 적용한 결과, 화질 저하가 거의 없이 화소 비교 연산량과 탐색 영역 데이터 액세스를 1/3.7 ~ 1/2.9로 줄였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 신호처리소사이어티 추계학술대회 논문집
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• pp.433-436
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• 2003

In this paper, the efficient motion estimation and compensation method for 3 dimensional wavelet transform is proposed. Recently, since the compression performance and scalable functionality are provided by wavelet transform, many researches have been carried out for applying to the video compression. For the temporal filtering, motion estimation and compensation techniques are used, but the unconnected pixels, which are produced by motion compensation result into the degradation of coding performance and quality of the picture. For the efficient motion compensated temporal filtering by reducing the number of these unconnected pixels, we propose the variable block size motion estimation and compensation method. Also we propose a method that determines the block size using rate-distortion optimization technique according to the local characteristics of the frame. The simulation results show the improved performances than the MPEG-4 scalable coding methods and the 3 dimensional wavelet coding methods using fixed block size motion estimation and compensation.

• Journal of the Optical Society of Korea
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• 제19권5호
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• pp.537-543
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• 2015

Liquid crystal displays (LCDs) have slow responses, so motion blurs are often perceived in fast moving scenes. To reduce this motion blur, we propose a novel method of robust motion compensated frame interpolation (MCFI) based on bidirectional motion estimation (BME) and weight-overlapped block motion compensation (WOBMC) with variable block sizes. In most MCFI methods, a static block size is used, so some block artefacts and motion blurs are observed. However, the proposed method adjusts motion block sizes and search ranges by comparing matching scores, so the precise motion vectors can be estimated in accordance with motions. In the MCFI, overlapping ranges for WOBMC are also determined by adjusted block sizes, so the accurate MCFI can be performed. In the experimental results, the proposed method strongly reduced motion blurs arisen from large motions, and yielded interpolated images with high visual performance and peak signal-to-noise ratio (PSNR).